A pbfi IMINARY MAP OF THE BADLAND FORMATIONS OF THE BLACK HILLS REGION 



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Mostly Lower Miocene. Known to contain some Upper M'ocene 

 Pliocene, and Pleistocene. Possibly includes also some 

 Middle Miocene. 



Non-differentiated Oligocene (Chiefly Chadron Formation.) 



Middle and Upper Oligocene. Brule Formation (Oreodon and 

 Protoceras Beds). 



Lower Oligocene. Chadron Formation (Titanotherium Beds.) 



